Flash Flood Warning 24, NWS Sioux Falls, SD

000 
WGUS73 KFSD 112152
FFSFSD

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
452 PM CDT FRI SEP 11 2009

IAC193-NEC043-SDC127-112207-
/O.EXP.KFSD.FF.W.0024.000000T0000Z-090911T2200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WOODBURY IA-DAKOTA NE-UNION SD-
452 PM CDT FRI SEP 11 2009

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR SOUTHEASTERN
UNION...EASTERN DAKOTA AND WESTERN WOODBURY COUNTIES WILL BE ALLOWED
TO EXPIRE AT 500 PM CDT...

EXCESS RUNOFF FROM HEAVY RAIN HAS ENDED OVER THE WARNED AREA. STREAMS
AND CREEKS IN THE WARNED AREA HAVE RECEDED OR WERE BEGINNING TO
RECEDE...ENDING THE FLOOD THREAT. IF FLOODING HAS BEEN OBSERVED...
PLEASE REPORT IT TO YOUR LOCAL LAW ENFORCEMENT AGENCY.

LAT...LON 4228 9653 4260 9664 4251 9626 4226 9612

$$

JM

AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NATIONAL WEATHER SERVICE SIOUX FALLS SD
315 PM CDT FRI SEP 11 2009

.DISCUSSION...
BAND OF SHOWERS AND THUNDERSTORMS CONTINUES TO SLOWLY WORK SOUTHEAST
AS UPPER LEVEL LOW PRESSURE SLOWS ITS EASTWARD MOVEMENT. A BAND OF
LOW TO MID LEVEL INSTABILITY ENOUGH TO KEEP THINGS GOING OVER THE
SOUTHERN THIRD OF THE CWA THROUGH THE EVENING WITH SOME SCATTERED
THUNDERSTORMS ALSO EXTENDING NORTH INTO SW MN ALONG AND NEAR THE SFC
TO NEAR SFC BOUNDARY. INSTABILITY NOT REAL IMPRESSIVE...BUT POSSIBLY
ENOUGH TO SUPPORT QUARTER SIZED HAIL AND WIND GUSTS TO 60 MPH. HEAVY
RAIN WILL ALSO BE A THREAT IN THESE AREAS WITH PWATS AROUND AN INCH
AND A HALF AND CAPE VALUES AROUND A THOUSAND. WARM CLOUD DEPTH
AROUND 11 KFT AGL...SO NOT OVERLY SUPPORTIVE OF EXCESSIVE TROPICAL
LIKE RAINS...BUT ENOUGH FOR SOME LOCALIZED PONDING AND ROAD
PROBLEMS. OTHERWISE...LEFT THE SKY MOSTLY CLOUDY THROUGH THE NIGHT
FOR THE EASTERN HALF OF THE CWA WHILE THE WEST WILL SEE SOME DROP IN
DIURNAL CU COVERAGE EARLY THIS EVENING...BUT COULD BE INFLUENCED BY
SOME CLOUD COVER FROM THE NORTH AS THE COLD AIR WRAPS SOUTH. MADE
VERY FEW CHANGES TO LOWS WITH LOWER 50S IN THE WEST AND MID TO UPPER
50S IN THE EAST.

AS UPPER LOW BEGINS TO MOVE WWD SAT...BAND OF MOISTURE AND WEAK
INSTBLTY WILL LINGER OVER ERN PART OF FCST AREA..AND FIGURE SHWR
DVMLPMNT SHUD BE CONFINED TO THAT AREA. ISOLD TSTMS PSBL WITH THE
SHWRS. THIS ACTVTY SHUD END SAT EVE. LO LVL MOISTURE WILL LINGER E
AND WITH LIGHT WINDS WILL GO WITH PATCHY FOG MAINLY E LATE SAT NGT
INTO ERY SUN MRNG. FOR REST OF SUN...WITH CONTD MIGRATION OF UPPER
LOW WWD AM TEMPTED TO TAKE OUT THE SLGT CHC SHWRS WE HAD...WILL
JUST LEAVE IN ALG THE MO RVR FOR NOW IN DEFERENCE TO MOISTURE THE
NAM IS SHOWING PERSISTING ON NRN END OF ELONGATED CNTRL/SRN PLAINS
LOW. GFS DRIES AREA OUT QUITE A BIT STGR BUT FOR ONLY A 20 PCT CHC
IT SEEMS BEST TO KEEP THE MENTN IN THAT AREA.

TEMPS OVER THE WEEKEND WILL BE A PRETTY STANDARD 50S FOR LOWS AND
70S FOR HIGHS...BUT SUN WILL PRBLY BE ON THE WARMER EDGE OF THOSE
70S AS UPPER RIDGING STARTS SLOWLY AS CURNT UPPER LOW MOVES WWD.
THIS RIDGING SHUD GRAB A STRONGER FOOTHOLD MON AND TUE WITH DRY WX
AND CONTD WARMING TO LVLS A LTL ABV NORMAL.

FOR WED THRU FRI PD WILL GO WITH EXTENDED GUIDNCE BRINGING SLIGHT
COOLING AND SOME CHC SHWRS AS REMNANTS OF UPPER LOW ROTATE OVER RDG
AND BACK DOWN THE E SIDE OF IT JUST E OF FCST AREA. LATEST ECMWF
KEEPS THE RIDGE IN STGLY AND NEVER LETS THIS OLD LOW DROP BACK
DOWN...KEEPING WX WARM AND DRY OVER AREA. THIS SOLUTION HASNT BEEN
SHOWN WITH CONSISTENCY YET SO WILL GO WITH THAT FIRST MENTND SOLN.

&&

.AVIATION...
MAINLY VFR THROUGH THE AFTERNOON...ALTHOUGH SOME HIGH END MVFR
CEILINGS POSSIBLE IN THE STRONGER THUNDERSTORMS. WILL HAVE TO KEEP
AN EYE OUT FOR SOME STRATUS AND FOG POTENTIAL LATE TONIGHT AS WINDS
DECOUPLE AND WEAKEN AND RELATIVELY MOIST ATMOSPHERE IS LEFT BEHIND.
BEST CHANCE SHOULD BE WHERE SKIES CLEAR AND PREVIOUS RAINS
FELL...BEST CHANCE AT THE HON TAF SITE.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...

SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.

&&

08/WILLIAMS

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1114 AM CDT FRI SEP 11 2009

SDZ038>040-050-052>071-MNZ071-072-080-081-089-090-097-098-
IAZ001>003-012>014-020>022-031-032-NEZ013-014-121200-
AURORA-BEADLE-BON HOMME-BROOKINGS-BRULE-BUENA VISTA IA-
CHARLES MIX-CHEROKEE IA-CLAY-CLAY IA-COTTONWOOD MN-DAKOTA NE-
DAVISON-DICKINSON IA-DIXON NE-DOUGLAS-GREGORY-HANSON-HUTCHINSON-
IDA IA-JACKSON MN-JERAULD-KINGSBURY-LAKE-LINCOLN-LINCOLN MN-
LYON IA-LYON MN-MCCOOK-MINER-MINNEHAHA-MOODY-MURRAY MN-NOBLES MN-
OBRIEN IA-OSCEOLA IA-PIPESTONE MN-PLYMOUTH IA-ROCK MN-SANBORN-
SIOUX IA-TURNER-UNION-WOODBURY IA-YANKTON-
1114 AM CDT FRI SEP 11 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST SOUTH DAKOTA...
SOUTHWEST MINNESOTA...NORTHWEST IOWA...AND NORTHEAST NEBRASKA.

.DAY ONE...TODAY AND TONIGHT

THUNDERSTORMS...
A BAND OF SHOWERS AND THUNDERSTORMS WILL CONTINUE TO SHIFT
SOUTHEAST THROUGH THE AFTERNOON. THE MAIN THREAT IN AND AROUND
THIS BAND WILL BE BRIEF HEAVY RAIN...POSSIBLY A HALF TO THREE
QUARTERS OF AN INCH IN ISOLATED SPOTS. AHEAD OF THIS BAND OVER
MAINLY PARTS OF NORTHWEST IOWA...A FEW THUNDERSTORMS COULD
DEVELOP AND POSSIBLY PRODUCE HAIL TO THE SIZE OF NICKELS OR
QUARTERS.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY AND TONIGHT.

&&

FOR MORE INFORMATION PLEASE VISIT OUR WEBSITE AT
WWW.WEATHER.GOV/SIOUXFALLS. THIS INCLUDES THE GRAPHICAL HAZARDOUS
WEATHER OUTLOOK.